I just Set up my 300GL tank the problem is water level on the tank does not reach at least half of the teeth of the built in overflow box its just barely 1/4 of the teeth the box has durso pipe measuring 1.25" that drains to a 75GL wet and dry filter that is run by 2 Quiet ones 4000...Question is how to raise the water level of the display tank? is my pump not powerful enough or are the drain pipes too big?